<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	

	
	<body>
<script>

function f(num){
	if(num<=1){
		return 1;
	}
	else{
		return f(num-1)*num;
		
	}
}





</script>
<script>

alert("10的结果为:"+f(10));

</script>





	</body>
</html>
